src/hardware/baylibre-acme/protocol.c

   1 /*
   2  * This file is part of the libsigrok project.
   3  *
   4  * Copyright (C) 2015 Bartosz Golaszewski <bgolaszewski@baylibre.com>
   5  *
   6  * This program is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <string.h>
  21 #include <stdlib.h>
  22 #include <errno.h>
  23 #include <fcntl.h>
  24 #include <glib/gstdio.h>
  25 #include "protocol.h"
  26 #include "gpio.h"
  27
  28 struct channel_group_priv {
  29         int hwmon_num;
  30         int probe_type;
  31         int index;
  32 };
  33
  34 struct channel_priv {
  35         int ch_type;
  36         struct channel_group_priv *probe;
  37 };
  38
  39 static const uint8_t enrg_i2c_addrs[] = {
  40         0x40, 0x41, 0x44, 0x45, 0x42, 0x43, 0x46, 0x47,
  41 };
  42
  43 static const uint8_t temp_i2c_addrs[] = {
  44         0x0, 0x0, 0x0, 0x0, 0x4c, 0x49, 0x4f, 0x4b,
  45 };
  46
  47 static const uint32_t pws_gpios[] = {
  48         486, 498, 502, 482, 478, 506, 510, 474,
  49 };
  50
  51 static const uint32_t pws_info_gpios[] = {
  52         487, 499, 503, 483, 479, 507, 511, 475,
  53 };
  54
  55 #define MOHM_TO_UOHM(x) ((x) * 1000)
  56 #define UOHM_TO_MOHM(x) ((x) / 1000)
  57
  58 SR_PRIV uint8_t bl_acme_get_enrg_addr(int index)
  59 {
  60         return enrg_i2c_addrs[index];
  61 }
  62
  63 SR_PRIV uint8_t bl_acme_get_temp_addr(int index)
  64 {
  65         return temp_i2c_addrs[index];
  66 }
  67
  68 SR_PRIV gboolean bl_acme_is_sane(void)
  69 {
  70         gboolean status;
  71
  72         /*
  73          * We expect sysfs to be present and mounted at /sys, ina226 and
  74          * tmp435 sensors detected by the system and their appropriate
  75          * drivers loaded and functional.
  76          */
  77         status = g_file_test("/sys", G_FILE_TEST_IS_DIR);
  78         if (!status) {
  79                 sr_err("/sys/ directory not found - sysfs not mounted?");
  80                 return FALSE;
  81         }
  82
  83         return TRUE;
  84 }
  85
  86 static void probe_name_path(unsigned int addr, GString *path)
  87 {
  88         g_string_printf(path,
  89                         "/sys/class/i2c-adapter/i2c-1/1-00%02x/name", addr);
  90 }
  91
  92 /*
  93  * For given address fill buf with the path to appropriate hwmon entry.
  94  */
  95 static void probe_hwmon_path(unsigned int addr, GString *path)
  96 {
  97         g_string_printf(path,
  98                         "/sys/class/i2c-adapter/i2c-1/1-00%02x/hwmon", addr);
  99 }
 100
 101 SR_PRIV gboolean bl_acme_detect_probe(unsigned int addr,
 102                                       int prb_num, const char *prb_name)
 103 {
 104         gboolean ret = FALSE, status;
 105         char *buf = NULL;
 106         GString *path = g_string_sized_new(64);
 107         GError *err = NULL;
 108         gsize size;
 109
 110         probe_name_path(addr, path);
 111         status = g_file_get_contents(path->str, &buf, &size, &err);
 112         if (!status) {
 113                 sr_dbg("Name for probe %d can't be read: %s",
 114                        prb_num, err->message);
 115                 g_string_free(path, TRUE);
 116                 return ret;
 117         }
 118
 119         if (!strncmp(buf, prb_name, strlen(prb_name))) {
 120                 /*
 121                  * Correct driver registered on this address - but is
 122                  * there an actual probe connected?
 123                  */
 124                 probe_hwmon_path(addr, path);
 125                 status = g_file_test(path->str, G_FILE_TEST_IS_DIR);
 126                 if (status) {
 127                         /* We have found an ACME probe. */
 128                         ret = TRUE;
 129                 }
 130         }
 131
 132         g_free(buf);
 133         g_string_free(path, TRUE);
 134
 135         return ret;
 136 }
 137
 138 static int get_hwmon_index(unsigned int addr)
 139 {
 140         int status, hwmon;
 141         GString *path = g_string_sized_new(64);
 142         GError *err = NULL;
 143         GDir *dir;
 144
 145         probe_hwmon_path(addr, path);
 146         dir = g_dir_open(path->str, 0, &err);
 147         if (!dir) {
 148                 sr_err("Error opening %s: %s", path->str, err->message);
 149                 g_string_free(path, TRUE);
 150                 return -1;
 151         }
 152
 153         g_string_free(path, TRUE);
 154
 155         /*
 156          * The directory should contain a single file named hwmonX where X
 157          * is the hwmon index.
 158          */
 159         status = sscanf(g_dir_read_name(dir), "hwmon%d", &hwmon);
 160         g_dir_close(dir);
 161         if (status != 1) {
 162                 sr_err("Unable to determine the hwmon entry");
 163                 return -1;
 164         }
 165
 166         return hwmon;
 167 }
 168
 169 static void append_channel(struct sr_dev_inst *sdi, struct sr_channel_group *cg,
 170                            int index, int type)
 171 {
 172         struct channel_priv *cp;
 173         struct dev_context *devc;
 174         struct sr_channel *ch;
 175         char *name;
 176
 177         devc = sdi->priv;
 178
 179         switch (type) {
 180         case ENRG_PWR:
 181                 name = g_strdup_printf("P%d_ENRG_PWR", index);
 182                 break;
 183         case ENRG_CURR:
 184                 name = g_strdup_printf("P%d_ENRG_CURR", index);
 185                 break;
 186         case ENRG_VOL:
 187                 name = g_strdup_printf("P%d_ENRG_VOL", index);
 188                 break;
 189         case TEMP_IN:
 190                 name = g_strdup_printf("P%d_TEMP_IN", index);
 191                 break;
 192         case TEMP_OUT:
 193                 name = g_strdup_printf("P%d_TEMP_OUT", index);
 194                 break;
 195         default:
 196                 sr_err("Invalid channel type: %d.", type);
 197                 return;
 198         }
 199
 200         cp = g_malloc0(sizeof(struct channel_priv));
 201         cp->ch_type = type;
 202         cp->probe = cg->priv;
 203
 204         ch = sr_channel_new(sdi, devc->num_channels++,
 205                             SR_CHANNEL_ANALOG, TRUE, name);
 206         g_free(name);
 207
 208         ch->priv = cp;
 209         cg->channels = g_slist_append(cg->channels, ch);
 210 }
 211
 212 SR_PRIV gboolean bl_acme_register_probe(struct sr_dev_inst *sdi, int type,
 213                                         unsigned int addr, int prb_num)
 214 {
 215         struct sr_channel_group *cg;
 216         struct channel_group_priv *cgp;
 217         int hwmon;
 218
 219         /* Obtain the hwmon index. */
 220         hwmon = get_hwmon_index(addr);
 221         if (hwmon < 0)
 222                 return FALSE;
 223
 224         cg = g_malloc0(sizeof(struct sr_channel_group));
 225         cgp = g_malloc0(sizeof(struct channel_group_priv));
 226         cgp->hwmon_num = hwmon;
 227         cgp->probe_type = type;
 228         cgp->index = prb_num - 1;
 229         cg->name = g_strdup_printf("Probe_%d", prb_num);
 230         cg->priv = cgp;
 231
 232         if (type == PROBE_ENRG) {
 233                 append_channel(sdi, cg, prb_num, ENRG_PWR);
 234                 append_channel(sdi, cg, prb_num, ENRG_CURR);
 235                 append_channel(sdi, cg, prb_num, ENRG_VOL);
 236         } else if (type == PROBE_TEMP) {
 237                 append_channel(sdi, cg, prb_num, TEMP_IN);
 238                 append_channel(sdi, cg, prb_num, TEMP_OUT);
 239         } else {
 240                 sr_err("Invalid probe type: %d.", type);
 241         }
 242
 243         sdi->channel_groups = g_slist_append(sdi->channel_groups, cg);
 244
 245         return TRUE;
 246 }
 247
 248 SR_PRIV int bl_acme_get_probe_type(const struct sr_channel_group *cg)
 249 {
 250         struct channel_group_priv *cgp = cg->priv;
 251
 252         return cgp->probe_type;
 253 }
 254
 255 SR_PRIV int bl_acme_probe_has_pws(const struct sr_channel_group *cg)
 256 {
 257         struct channel_group_priv *cgp = cg->priv;
 258
 259         return sr_gpio_getval_export(pws_info_gpios[cgp->index]);
 260 }
 261
 262 /*
 263  * Sets path to the hwmon attribute if this channel group
 264  * supports shunt resistance setting. The caller has to supply
 265  * a valid GString.
 266  */
 267 static int get_shunt_path(const struct sr_channel_group *cg, GString *path)
 268 {
 269         struct channel_group_priv *cgp;
 270         int ret = SR_OK, status;
 271
 272         cgp = cg->priv;
 273
 274         if (cgp->probe_type != PROBE_ENRG) {
 275                 sr_err("Probe doesn't support shunt resistance setting");
 276                 return SR_ERR_ARG;
 277         }
 278
 279         g_string_append_printf(path,
 280                                "/sys/class/hwmon/hwmon%d/shunt_resistor",
 281                                cgp->hwmon_num);
 282
 283         /*
 284          * The shunt_resistor sysfs attribute is available
 285          * in the Linux kernel since version 3.20. We have
 286          * to notify the user if this attribute is not present.
 287          */
 288         status = g_file_test(path->str, G_FILE_TEST_EXISTS);
 289         if (!status) {
 290                 sr_err("shunt_resistance attribute not present, please update "
 291                        "your kernel to version >=3.20");
 292                 return SR_ERR_NA;
 293         }
 294
 295         return ret;
 296 }
 297
 298 /*
 299  * Try setting the update_interval sysfs attribute for each probe according
 300  * to samplerate.
 301  */
 302 SR_PRIV void bl_acme_maybe_set_update_interval(const struct sr_dev_inst *sdi,
 303                                                uint64_t samplerate)
 304 {
 305         struct sr_channel_group *cg;
 306         struct channel_group_priv *cgp;
 307         GString *hwmon;
 308         GSList *l;
 309         FILE *fd;
 310
 311         for (l = sdi->channel_groups; l != NULL; l = l->next) {
 312                 cg = l->data;
 313                 cgp = cg->priv;
 314
 315                 hwmon = g_string_sized_new(64);
 316                 g_string_append_printf(hwmon,
 317                                 "/sys/class/hwmon/hwmon%d/update_interval",
 318                                 cgp->hwmon_num);
 319
 320                 if (g_file_test(hwmon->str, G_FILE_TEST_EXISTS)) {
 321                         fd = g_fopen(hwmon->str, "w");
 322                         if (!fd) {
 323                                 g_string_free(hwmon, TRUE);
 324                                 continue;
 325                         }
 326
 327                         g_fprintf(fd, "%" PRIu64 "\n", 1000 / samplerate);
 328                         fclose(fd);
 329                 }
 330
 331                 g_string_free(hwmon, TRUE);
 332         }
 333 }
 334
 335 SR_PRIV int bl_acme_get_shunt(const struct sr_channel_group *cg,
 336                               uint64_t *shunt)
 337 {
 338         GString *path = g_string_sized_new(64);
 339         gchar *contents;
 340         int status, ret = SR_OK;
 341         GError *err = NULL;
 342
 343         status = get_shunt_path(cg, path);
 344         if (status != SR_OK) {
 345                 ret = status;
 346                 goto out;
 347         }
 348
 349         status = g_file_get_contents(path->str, &contents, NULL, &err);
 350         if (!status) {
 351                 sr_err("Error reading shunt resistance: %s", err->message);
 352                 ret = SR_ERR_IO;
 353                 goto out;
 354         }
 355
 356         *shunt = UOHM_TO_MOHM(strtol(contents, NULL, 10));
 357
 358 out:
 359         g_string_free(path, TRUE);
 360         return ret;
 361 }
 362
 363 SR_PRIV int bl_acme_set_shunt(const struct sr_channel_group *cg, uint64_t shunt)
 364 {
 365         GString *path = g_string_sized_new(64);;
 366         int status, ret = SR_OK;
 367         FILE *fd;
 368
 369         status = get_shunt_path(cg, path);
 370         if (status != SR_OK) {
 371                 ret = status;
 372                 goto out;
 373         }
 374
 375         /*
 376          * Can't use g_file_set_contents() here, as it calls open() with
 377          * O_EXEC flag in a sysfs directory thus failing with EACCES.
 378          */
 379         fd = g_fopen(path->str, "w");
 380         if (!fd) {
 381                 sr_err("Error opening %s: %s", path->str, strerror(errno));
 382                 ret = SR_ERR_IO;
 383                 goto out;
 384         }
 385
 386         g_fprintf(fd, "%" PRIu64 "\n", MOHM_TO_UOHM(shunt));
 387         fclose(fd);
 388
 389 out:
 390         g_string_free(path, TRUE);
 391         return ret;
 392 }
 393
 394 SR_PRIV int bl_acme_read_power_state(const struct sr_channel_group *cg,
 395                                      gboolean *off)
 396 {
 397         struct channel_group_priv *cgp;
 398         int val;
 399
 400         cgp = cg->priv;
 401
 402         if (!bl_acme_probe_has_pws(cg)) {
 403                 sr_err("Probe has no power-switch");
 404                 return SR_ERR_ARG;
 405         }
 406
 407         val = sr_gpio_getval_export(pws_gpios[cgp->index]);
 408         *off = val ? FALSE : TRUE;
 409
 410         return SR_OK;
 411 }
 412
 413 SR_PRIV int bl_acme_set_power_off(const struct sr_channel_group *cg,
 414                                   gboolean off)
 415 {
 416         struct channel_group_priv *cgp;
 417         int val;
 418
 419         cgp = cg->priv;
 420
 421         if (!bl_acme_probe_has_pws(cg)) {
 422                 sr_err("Probe has no power-switch");
 423                 return SR_ERR_ARG;
 424         }
 425
 426         val = sr_gpio_setval_export(pws_gpios[cgp->index], off ? 0 : 1);
 427
 428         return SR_OK;
 429 }
 430
 431 static int channel_to_mq(struct sr_channel *ch)
 432 {
 433         struct channel_priv *chp;
 434
 435         chp = ch->priv;
 436
 437         switch (chp->ch_type) {
 438         case ENRG_PWR:
 439                 return SR_MQ_POWER;
 440         case ENRG_CURR:
 441                 return SR_MQ_CURRENT;
 442         case ENRG_VOL:
 443                 return SR_MQ_VOLTAGE;
 444         case TEMP_IN: /* Fallthrough */
 445         case TEMP_OUT:
 446                 return SR_MQ_TEMPERATURE;
 447         default:
 448                 return -1;
 449         }
 450 }
 451
 452 static int channel_to_unit(struct sr_channel *ch)
 453 {
 454         struct channel_priv *chp;
 455
 456         chp = ch->priv;
 457
 458         switch (chp->ch_type) {
 459         case ENRG_PWR:
 460                 return SR_UNIT_WATT;
 461         case ENRG_CURR:
 462                 return SR_UNIT_AMPERE;
 463         case ENRG_VOL:
 464                 return SR_UNIT_VOLT;
 465         case TEMP_IN: /* Fallthrough */
 466         case TEMP_OUT:
 467                 return SR_UNIT_CELSIUS;
 468         default:
 469                 return -1;
 470         }
 471 }
 472
 473 /* We need to scale measurements down from the units used by the drivers. */
 474 static float adjust_data(int val, int type)
 475 {
 476         switch (type) {
 477         case ENRG_PWR:
 478                 return ((float)val) / 1000000.0;
 479         case ENRG_CURR: /* Fallthrough */
 480         case ENRG_VOL: /* Fallthrough */
 481         case TEMP_IN: /* Fallthrough */
 482         case TEMP_OUT:
 483                 return ((float)val) / 1000.0;
 484         default:
 485                 return 0.0;
 486         }
 487 }
 488
 489 static float read_sample(struct sr_channel *ch)
 490 {
 491         struct channel_priv *chp;
 492         char path[64], *file, buf[16];
 493         ssize_t len;
 494         int fd;
 495
 496         chp = ch->priv;
 497
 498         switch (chp->ch_type) {
 499         case ENRG_PWR:  file = "power1_input";  break;
 500         case ENRG_CURR: file = "curr1_input";   break;
 501         case ENRG_VOL:  file = "in1_input";     break;
 502         case TEMP_IN:   file = "temp1_input";   break;
 503         case TEMP_OUT:  file = "temp2_input";   break;
 504         default:
 505                 sr_err("Invalid channel type: %d.", chp->ch_type);
 506                 return -1.0;
 507         }
 508
 509         snprintf(path, sizeof(path), "/sys/class/hwmon/hwmon%d/%s",
 510                  chp->probe->hwmon_num, file);
 511         fd = open(path, O_RDONLY);
 512         if (fd < 0) {
 513                 sr_err("Error opening %s: %s", path, strerror(errno));
 514                 ch->enabled = FALSE;
 515                 return -1.0;
 516         }
 517
 518         len = read(fd, buf, sizeof(buf));
 519         close(fd);
 520         if (len < 0) {
 521                 sr_err("Error reading from %s: %s", path, strerror(errno));
 522                 ch->enabled = FALSE;
 523                 return -1.0;
 524         }
 525
 526         return adjust_data(strtol(buf, NULL, 10), chp->ch_type);
 527 }
 528
 529 SR_PRIV int bl_acme_receive_data(int fd, int revents, void *cb_data)
 530 {
 531         uint32_t cur_time, elapsed_time, diff_time;
 532         int64_t time_to_sleep;
 533         struct sr_datafeed_packet packet, framep;
 534         struct sr_datafeed_analog analog;
 535         struct sr_dev_inst *sdi;
 536         struct sr_channel *ch;
 537         struct dev_context *devc;
 538         GSList *chl, chonly;
 539         float valf;
 540
 541         (void)fd;
 542         (void)revents;
 543
 544         sdi = cb_data;
 545         if (!sdi)
 546                 return TRUE;
 547
 548         devc = sdi->priv;
 549         if (!devc)
 550                 return TRUE;
 551
 552         packet.type = SR_DF_ANALOG;
 553         packet.payload = &analog;
 554         memset(&analog, 0, sizeof(struct sr_datafeed_analog));
 555         analog.data = &valf;
 556
 557         /*
 558          * Reading from sysfs takes some time - try to keep up with samplerate.
 559          */
 560         if (devc->samples_read) {
 561                 cur_time = g_get_monotonic_time();
 562                 diff_time = cur_time - devc->last_sample_fin;
 563                 time_to_sleep = G_USEC_PER_SEC / devc->samplerate - diff_time;
 564                 if (time_to_sleep > 0)
 565                         g_usleep(time_to_sleep);
 566         }
 567
 568         framep.type = SR_DF_FRAME_BEGIN;
 569         sr_session_send(cb_data, &framep);
 570
 571         /*
 572          * Due to different units used in each channel we're sending
 573          * samples one-by-one.
 574          */
 575         for (chl = sdi->channels; chl; chl = chl->next) {
 576                 ch = chl->data;
 577                 if (!ch->enabled)
 578                         continue;
 579                 chonly.next = NULL;
 580                 chonly.data = ch;
 581                 analog.channels = &chonly;
 582                 analog.num_samples = 1;
 583                 analog.mq = channel_to_mq(chl->data);
 584                 analog.unit = channel_to_unit(ch);
 585
 586                 valf = read_sample(ch);
 587
 588                 sr_session_send(cb_data, &packet);
 589         }
 590
 591         framep.type = SR_DF_FRAME_END;
 592         sr_session_send(cb_data, &framep);
 593
 594         devc->samples_read++;
 595         if (devc->limit_samples > 0 &&
 596             devc->samples_read >= devc->limit_samples) {
 597                 sr_info("Requested number of samples reached.");
 598                 sdi->driver->dev_acquisition_stop(sdi, cb_data);
 599                 devc->last_sample_fin = g_get_monotonic_time();
 600                 return TRUE;
 601         } else if (devc->limit_msec > 0) {
 602                 cur_time = g_get_monotonic_time();
 603                 elapsed_time = cur_time - devc->start_time;
 604
 605                 if (elapsed_time >= devc->limit_msec) {
 606                         sr_info("Sampling time limit reached.");
 607                         sdi->driver->dev_acquisition_stop(sdi, cb_data);
 608                         devc->last_sample_fin = g_get_monotonic_time();
 609                         return TRUE;
 610                 }
 611         }
 612
 613         devc->last_sample_fin = g_get_monotonic_time();
 614         return TRUE;
 615 }